This invention relates to a disposable syringe of the prefilled type. More particularly it relates to a prefilled, disposable syringe wherein the medicament contained in the syringe is held under isolated maximum sterile conditions until it is desired to premix it with a diluent material, the syringe being completely preassembled and affording positive piercing sequencing by means of a piercing tubular member which is positioned in a telescoping guide member between two sealing stoppers which separate the compartments for the diluent and the medicament.
There are currently available many types of disposable syringes wherein a medicament is sealed in the syringe barrel to be later combined with a diluent for the material in the syringe barrel. There are also available unitary containers which contain a medicament and a diluent for it in two different compartments which are then intermixed prior to their usage. However, many of these devices which are now available either do not afford positive intermixing between the two materials, are costly to manufacture because of the necessity of utilizing many component parts, are complicated in their usage because of many parts being involved or after intermixing in a container still require a syringe for injection. For example, in U.S. Pat. Nos. 2,684,068; 3,098,483 and 3,327,710, combination hypodermic syringes and mixing containers are disclosed. However, these units do not afford complete separation of one of the materials to be mixed from the piercing cannula or tube so that sterility and complete mixing can be a problem. Further, many of these units as well as one of the units described in U.S. Pat. No. 3,542,023 do not afford positive engagement and sequencing of the various compartments for the components to assure their intermixing.
Positive intermixing is also a factor in U.S. Pat. Nos. 3,724,460 and 3,636,950 which while employing a multitude of components still do not afford a positive sequencing action in one unit. In U.S. Pat. Nos. 3,489,147 and 3,477,432, multicomponent combination mixing and administration syringes are disclosed. However, various manipulations of these units must be made in order to activate them.
Further, in U.S. Pat. No. 3,895,633, a specifically designed friction-type sliding fitment is provided for actuation of a needle through a pierceable stopper. In U.S. Pat. No. 4,014,330, a double-pointed cannula is anchored in a sliding member for piercing through two stoppers, one of which is contained in a slidably receivable vial. None of the prior art previously discussed provides a preassembled syringe unit having an inner barrel member within an outer barrel and a telescoping-type piercing action of a double-pointed cannula to interconnect the two chambers within the syringe.
It is an advantage of the present invention to provide a novel preassembled mixing and hypodermic syringe which affords maximum isolation and sterility of two components which are to be ultimately mixed, and positive sequencing of the intermixing. Other advantages are a syringe which is completely preassembled, a syringe which utilizes a unique telescoping arrangement of the double-pointed cannula for piercing through the two stoppers in the syringe separating the two components, a syringe which requires a minimum of manipulative steps for actuation and a minimum amount of space for packaging.